Why not just put the music directly on the device that you want to use for music? I feel like that would be a lot more efficient. Also, I use the site convert2mp3.net and I find that it works out well for me. It can be used to convert more than just YouTube videos as well, though I've only used YouTube as I find it the best. You can put it to mp3 or mp4 files as well. For those who don't know what that means, you can have a sound or video file.